Baseline study - projection on zika spread in US, Aedes populations

[jim mcnamara]

Washington Post:
https://www.washingtonpost.com/news...-cities-that-could-be-hit-by-a-zika-outbreak/

Study:
http://currents.plos.org/outbreaks/...edes-aegypti-in-the-contiguous-united-states/

Abstract:

Introduction: An ongoing Zika virus pandemic in Latin America and the Caribbean has raised concerns that travel-related introduction of Zika virus could initiate local transmission in the United States (U.S.) by its primary vector, the mosquito Aedes aegypti.

Methods: We employed meteorologically driven models for 2006-2015 to simulate the potential seasonal abundance of adult Aedes aegypti for fifty cities within or near the margins of its known U.S. range. Mosquito abundance results were analyzed alongside travel and socioeconomic factors that are proxies of viral introduction and vulnerability to human-vector contact.

Results: Meteorological conditions are largely unsuitable for Aedes aegypti over the U.S. during winter months (December-March), except in southern Florida and south Texas where comparatively warm conditions can sustain low-to-moderate potential mosquito abundance. Meteorological conditions are suitable for Aedes aegypti across all fifty cities during peak summer months (July-September), though the mosquito has not been documented in all cities. Simulations indicate the highest mosquito abundance occurs in the Southeast and south Texas where locally acquired cases of Aedes-transmitted viruses have been reported previously. Cities in southern Florida and south Texas are at the nexus of high seasonal suitability for Aedes aegypti and strong potential for travel-related virus introduction. Higher poverty rates in cities along the U.S.-Mexico border may correlate with factors that increase human exposure to Aedes aegypti.

Discussion: Our results can inform baseline risk for local Zika virus transmission in the U.S. and the optimal timing of vector control activities, and underscore the need for enhanced surveillance for Aedes mosquitoes and Aedes-transmitted viruses.

 

[Ygggdrasil]

The Zika virus may reveal the shortsightedness of many states' budgetary planning. According to National Geographic:

In 2014, the Council of State and Territorial Epidemiologists examined staffing and budgets for mosquito control in state and large city health departments, comparing levels in 2012 and in 2004, the year that West Nile virus spread to all of the lower 48 states. They found dismaying drops:

• Overall federal funding down 60 percent, from $24 million to $10 million.
• Number of staff working at least half-time on West Nile surveillance: down 41 percent.
• Proportion of states conducting mosquito surveillance: down from 96 percent to 80 percent.
• States that had reduced mosquito trapping: 58 percent; states that had reduced mosquito testing: 68 percent.
• States that had reduced testing of human patients suspected of having West Nile: 46 percent.

Indeed, the state of North Carolina entirely eliminated[/PLAIN] all of the states' mosquito control programs:

Two different programs aimed at controlling mosquitoes and other pests were pared back, and then finally eliminated, under Gov. Bev Perdue, a Democrat, and Republican Gov. Pat McCrory, as both governors and the General Assembly struggled to get a hold on budget shortfalls that were symptoms of the recession.

In 2010, Perdue and the Democratic majority in the General Assembly made the first cut to grants that helped local governments control mosquitoes. In 2011, a Republican-controlled General Assembly voted to eliminate the "vector control program," which monitored and analyzed the spread of mosquitoes as part of what is now the Department of Environmental Quality. The last of the mosquito control grants for local governments were eliminated in 2014.

While funding for these programs can be restored, it may not be possible to recover the expertise held by the individuals laid off, and it's unclear whether states would be able to train enough new staff in time.